Relay magnetic frame and armature arrangement

ABSTRACT

An arrangement for the magnetic frame and armature of a relay which upon impact of the armature against the frame allows for a wiping action between the engaging faces of the frame and the armature.

United States Patent Kane et al. [4 1 May 16, 1972 [54] RELAY MAGNETIC FRAME AND [56] Referenc cued ARMATURE ARRANGEMENT UNITED STATES PATENTS Inventors: g Rene: George R n, both 3,334,319. 8/1967 Herrmann etal ..335/132 x of P 3,196,231 7/1965 Meyer 73 Assignee; H Inc Minneapolis, Minn 3,453,571 7/1969 Koertge "335/132 [22] Filed: Sept 1970 Primary Examiner-George Harris [21 Appl. No.: 71,457 Attorney-Lamont B. Koontz and Philip J. Zrimsek ABSTRACT [52] U.S.Cl ..335/27l, 335/277, 335/193 n ng m n r he magne ic frame and armature of a 51 1 1m. 01. .1101: 7/08 relay which p impact of the armature against the frame [58] Field of Search ..335/270, 271, 277, 257, 255 lows for a wiping c ion b tween the engaging faces of the 335/132, 193 frame and the armature.

7 Claims, 4 Drawing Figures PATENTEB YI IB 3.663.908

FT'gcZ {W liiliii WWW . HUM! INVEN R5. 1 GEORGE W. RIC RDSON HUGH KANE RELAY MAGNETIC FRAME AND ARMATURE ARRANGEMENT This invention is concerned with an arrangement for the magnetic frame and armature of a relay which minimizes damage caused by impact to the engaging faces of the frame and the armature due to a rocking motion introduced to the frame and the armature upon impact resulting in a wiping action between the engaging faces thereof.

Relays have long been provided with shock absorbing means to reduce the effect of impact between the magnetic frame and the armature and to minimize contact bounce. Usually the shock absorbing means has taken the form of a resilient pad or spring member disposed between the magnetic frame and the support member carrying it. Such shock absorbing means generally utilize energy dissipation over a time span based upon damping of the system to accomplish the assigned function. While such forms of shock absorbing means are advantageous in terms of energy dissipation and minimization of contact bounce, damage to the engaging faces of the magnetic frame and armature in the form of mushrooming" tends to arise.

In the present invention, an arrangement is provided which while it may include shock absorbing means utilizing damping to partially accomplish the assigned function, it need only involve a wiping action between the faces of and the utilization of the electromagnetic forces set up between the faces of the magnetic frame and the armature to dissipate the energy of impact introduced.

In the preferred embodiment, the faces of the magnetic frame and the armature engage upon impact. and a frictional wiping action therebetween arises due to a rocking movement of the armature and a like movement of the frame against shock absorbing means. The wiping action provides relative movement between the engaging faces of the magnetic frame and armature which movement is substantially at right angles to the electromagnetic lines of force passing through the faces, which in the first instance caused the engagement and the impact of the frame and armature. The frictional wiping action and the cutting of the electromagnetic lines of force due to the wiping action involves dissipation of the energy of impact in a manner which reduces to a minimum the mushrooming effects normally encountered due to impact engagement of the faces of the magnetic frame and armature.

Therefore, it is an object of the present invention to provide an arrangement for a relay which is efiective upon engagement of the faces of the magnetic frame and the armature to dissipate the energy of impact in a manner which involves a frictional wiping action between the engaging faces of the frame and armature requiring the overcoming of electromagnetic lines of force that pass between the engaging faces.

These and other objects will become apparent from a reading of the following specification and claims when viewed with the drawing in which:

FIG. 1 is a perspective view of a relay of the type in which the invention disclosed herein finds application;

FIG. 2 is a cross-sectional view on an enlarged scale of the relay of FIG. 1 along the lines 2-2 thereof showing the invention including a first form of shock absorbing means;

FIG. 3 is a partial crosssectional view taken along the lines 3-3 of FIG. 2; and

FIG. 4 is a perspective view of a second sorbing means.

Referring to FIGS. 1, 2 and 3, a multipole relay 10, is shown having a support or base 12 with a cavity 12a in which a magnetic E frame 14 is secured, as will be detailed below, about the center leg of which a tubular coil 16 is disposed. Straddling and pivotally associated with the lower portions of the base 12 are a pair of bifurcated split housings l8 and 20, the upper portions 18a and 20a, respectively, of which overlay the cavity 12a of the base 12. The housings l8 and 20 support a plurality of terminal members 22 each of which include a fixed contact portion 22a and further support coil terminals 24. Interior spring extensions 24a of the coil terminals 24 are arranged to form of shock abappropriately electrically engage butt terminals, not shown, located on the top surface of the coil 16 and also serve to maintain the coil in proper position in the cavity 12a of the base 12. Disposed between the housings l8 and 20 and arranged for association and relative inward and outward reciprocal movement therewith and with said base 12 is an assembly comprised of an armature 28, a bias plate 30 and a bifurcated moving contact carrier 32. A plurality of U-shaped moving contact bridging bars 34 are supported by the moving contact carrier 32 and the extremities are arranged for association with a respective pair of fixed contact portions 22a to provide the switching function. The armature 28 and the moving contact carrier 32 are suitably joined together as will be detailed below with the bias plate 30 resiliently disposed therebetween for limited relative reciprocal movement therewith as will become apparent below.

The bias plate 30 is seated on posts 12b and 12c of the base and overlaid by the portions 18a and 20a of the housings l8 and 20, respectively, so as to be maintained as a prisoner therebetween. Further, the leg portions 32a of the moving contact carrier 32 are guided in slots 12d of the base 12 and between opposite guide surfaces 18b and 20b of the housings l8 and 20, respectively, so as to allow for reciprocal movemerits of the carrier and the associated armature 28 toward and away from the magnetic frame 14 upon energization and de-energization of the coil 16. Inward reciprocal movement of the armature 28 and the moving contact carrier 32 from the at rest position" shown upon energization of coil 16 results in relative movement with the bias plate 30 and the generation of a return force caused by spring means, not shown, disposed between the carrier and the bias plate being compressed. Consequently, outward reciprocal movement upon de-energization of coil 16 is provided by the return force. Such reciprocal movements of course cause a change in the condition of the poles formed of the respective sets of fixed contact portions 22a and bridging bars 34.

The foregoing general description is merely to set a framework for the invention and as such forms no real part of it. The inventive concept is set forth below.

Referring now only to FIGS. 2 and 3, the magnetic frame 14 is disposed upon a shock absorbing means which takes the form of a coil spring 36 appropriately located in depression 12c of the base 12 and disposed to one side of the center leg of the frame and a resilient pad 38 appropriately secured to surface 12f of the base and disposed to the other side of the center leg of the frame. A plate 40 with a central aperture 40a is disposed over and about the center leg of the magnetic frame 14 and is secured by conventional fasteners, not shown, to posts 12g of the base 12 so as to bear against the frame to limit the upward movement and position thereof. Because the spring rate of the spring 36 is chosen to be somewhat less than that of the pad 38, the magnetic frame 14 can pivot or rock about the pad and about an axis which is generally transverse to the path of the reciprocal movements of the armature 28 towards and away therefrom and further is transverse to the longitudinal dimension thereof.

The armature 28 includes a shouldered opening 28a which is arranged to accommodate stepped portion 32b of the moving contact carrier 32. Spring member 42 formed of flat material is disposed between the lower surface of the shouldered opening 280 and the lower surface of the stepped portion 32b. It will be noted that the downwardly extending fingers 42a of the spring member 42 straddle the armature 28 and that the apex 42b of the spring member is seated in a corresponding depression 32c located in the lower surface of the stepped portion 32a. This interrelationship along with the bias provided by the spring member 42 acting on and between the lower surface of the shouldered opening 28a and the depression 32c of the lower surface of the stepped portion 32b ensures an adequate juncture between the armature 28 and the moving contact carrier 32. Further, the relationship between the armature 28, the moving contact carrier 32 and the spring member 42 just described allows for a pivotal or rocking movement of the armature with respect to the moving contact carrier about an axis which is generally transverse to its path of reciprocal movements toward and away from the magnetic frame 14 and further is transverse to the longitudinal dimension thereof.

With the magnetic frame 14 and the armature 28 supported as just set forth, energization of the coil 16 results in impact engagement between the oppositely disposed faces of the frame and the armature and rocking movement of the frame and the armature with consequent relative wiping movement provided between the engaging faces. Thus, upon energization of the coil 16 and the engagement of the oppositely disposed faces of the magnetic frame 14 and the armature 28, the initial impact may cause a downward straight line movement of the frame and armature until such time as the different spring rates of the coil spring 36 and the resilient pad 38 come into play. Thereafter the magnetic frame 14 begins to undergo pivotal movement about the pad 38 since the spring rate of the pad is greater than that of the spring 36. As the armature 28 is free to pivot, it follows the pivotal movement of the magnetic frame 14 whereby extremity 320 of the stepped portion 32a of the moving contact carrier 32 pivots on extremity 28b of the shouldered opening 28a of the armature 28 and extremity 28c of the shouldered opening moves away from extremity 32d of the stepped portion against the bias of spring member 42. While the magnetic frame 14 and the armature 28 pivot about displaced although co-extensive axes, the pivotal movement of these elements is quite limited. Consequently, for all practical purposes, the pivoting of the magnetic frame 14 and the armature 28 can be considered to be complementary and of such a character that the faces thereof are in constant engagement and undergo a constant frictional wiping action as the pivoting takes place.

The compression of the coil spring 36 and the resilient pad 38 which results as a reaction to the downward straight line and pivotal movement of the magnetic frame 14 and the ensuing frictional wiping action gives rise to dissipation of some of the energy of impact. Additional dissipation of the energy of impact arises as a result of the wiping action due to work expended in cutting lines of electromagnetic force. These lines exist between the engaging faces of the magnetic frame 14 and the armature 28 because of the energization of the coil 16 and are at substantially right angles to the wiping action.

As the downward pivotal movement of the armature 28 continues due to the energization of the coil 16, the complementary pivoting of the magnetic frame 14 and the armature continues until the energy of impact is dissipated or until the frame bottoms" on the surface 12f of the base 12. If bottoming occurs, of course rebound of the magnetic frame 14 and the armature 28 arises and a reverse wiping action takes place. In any event, ultimately a steady state condition arises but it is brought about without the usual adverse mushrooming" effects to the engaging faces of the magnetic frame 14 and the armature 28 as the wiping action with the consequent dissipation of impact energy precludes such efiects from arising.

It will be appreciated that the resultant force or line of action of the armature 28 in its path of movement upon engagement with the magnetic frame 14 must be so offset from the pivotal axis of the frame as to provide a moment of force acting on the frame which will give rise to the rocking movement of the frame and consequently the armature with the resulting wiping action.

Other forms of shock absorbing means are possible, attention now being directed to FIG. 4. There a flat spring 50 provides the function of the coil spring 36 and resilient pad 38 shown in FIGS. 2 and 3. Thus the flat spring 50 is provided with a smooth curvature portion 50a and a crimped portion 50b for disposal to either side of the center leg of the magnetic frame 14 of FIGS. 2 and 3. The curvature portion 50a is provided so as to have a spring rate greater than the crimped portion 50b whereby the spring member 50 can provide the same function in the relay 10 as that provided by the combination of the spring 36 and the pad 38.

In the preferred embodiment, a shock absorbing means has been utilized to allow for rocking of the magnetic frame member 14 but it will be understood that such means is not required where the energy dissipated by the frictional wiping action and the energy dissipated by the cutting of electromagnetic lines of force completely absorbs the energy of impact. In such a configuration the magnetic frame member 14 would of course require another form of pivotal means.

While a preferred embodiment has been disclosed herein, other forms of the invention are possible and therefore the I scope thereof should be determined from the following claims.

I claim:

1. In a relay, the arrangement comprising: a magnetic annature; a support; a magnetic frame carried by said support and arranged for impact engagement by said armature; said armature arranged to rock about an axis transverse to its path of movement towards and away from said frame; said frame arranged to rock in said support about an axis parallel to and coextensive with the forementioned axis; the line of action of said armature in its path of movement upon engagement with said frame being such as to provide a moment acting on said frame causing rocking movements thereof resulting in a wiping action between the engaging faces of said frame and annature so as to minimize damage thereto and so as to dissipate the energy of impact by the wiping action which is at substantially right angles to the electromagnetic lines of force passing through the engaging faces of said armature and frame.

2. The arrangement of claim 1 wherein shock absorbing means is associated with said frame and said armature so as to react against the impact and the resultant rocking thereof.

3. The arrangement of claim 2 wherein said shock absorbing means is disposed between said support and said frame.

4. The arrangement of claim 3 wherein said armature and said frame are of similar multilegged form and the path of movement of said armature is substantially reciprocal.

5. The arrangement of claim 4 wherein said shock absorbing means includes a first resilient member about which the rocking of said frame takes place and a second more resilient member displaced from said first member.

6. The arrangement of claim 5 wherein said resilient member is in the form of a coil spring.

7. The arrangement of claim 4 wherein said shock absorbing means is in the form of a flat spring member which includes a first resilient portion about which the rocking of said frame takes place and a second more resilient portion displaced from said first portion. 

1. In a relay, the arrangement comprising: a magnetic armature; a support; a magnetic frame carried by said support and arranged for impact engagement by said armature; said armature arranged to rock about an axis transverse to its path of movement towards and away from said frame; said frame arranged to rock in said support about an axis parallel to and co-extensive with the forementioned axis; the line of action of said armature in its path of movement upon engagement with said frame being such as to provide a moment acting on said frame causing rocking movements thereof resulting in a wiping action between the engaging faces of said frame and armature so as to minimize damage thereto and so as to dissipate the energy of impact by the wiping action which is at substantially right angles to the electromagnetic lines of force passing through the engaging faces of said armature and frame.
 2. The arrangement of claim 1 wherein shock absorbing means is associated with said frame and said armature so as to react against the impact and the resultant rocking thereof.
 3. The arrangement of claim 2 wherein said shock absorbing means is disposed between said support and said frame.
 4. The arrangement of claim 3 wherein said armature and said frame are of similar multilegged form and the path of movement of said armature is substantially reciprocal.
 5. The arrangement of claim 4 wherein said shock absorbing means includes a first resilient member about which the rocking of said frame takes place and a second more resilient member displaced from said first member.
 6. The arrangement of claim 5 wherein said resilient member is in the form of a coil spring.
 7. The arrangement of claim 4 wherein said shock absorbing means is in the form of a flat spring member which includes a first resilient portion about which the rocking of said frame takes place and a second more resilient portion displaced from said first portion. 